The interaction of particles of the same type but of positive and negative sign is the same, except for the fact that the force on the negative particle is in the reversed direction of the force on the positive particle. This conclusion was from the post "Sunshine and Proton Beam Corrected" dated 30 Jun 2015.
So, a negative particle with higher \(\psi\) will move into the direction of lesser \(\psi\) around a positive particle. A negative particle of with lower \(\psi\) will move into the direction of higher \(\psi\) around a positive particle. The result is the repulsion of the two particles in the region \(x\gt x_z\) (beyond \(\psi_{max}\)), when the negative particle has higher energy density. Beyond \(\psi\) the force is attractive (the sign of \(F\) flipped twice, once due to \(-\psi\) another because of the reverse in direction due to the negative particle). And when the negative particle has lower energy density, it accelerate further into the positive particle and would oscillate about \(\psi_{max}\) of the positive particle.
An electron with comparatively less mass, has less mass density and so, would have higher energy density than a proton. (c/f post "We Still Have A Problem" dated 23 Nov 2014.) Repulsion between an electron and a proton is the norm.
An example of a negative particle oscillating inside the \(\psi\) of a positive particle is the case of an unstable nucleus, when an electron get absorbed into the nucleus. This electron will have higher mass density than normal electrons, such that its has lower energy density than the proton.
A negative particle of less energy density oscillating inside the \(\psi\) cloud of a positive particle is one more scenario where a negative particle and a positive particle can be bounded. Another being one particle in orbit around the other.
